const angleToSin = (angle) => Math.sin(Math.PI / 180 * angle)

const checkIsRightTriangle = (a, b, c) =>
    (a ** 2 + b ** 2).toFixed(2) === (c ** 2).toFixed(2)

const computeAngleC = () => {
    const AB = 1
    const BAD = 60
    for (let i = 1; i < 180; i++) {
        const C = i
        const B = 180 - 90 - C
        const ADB = 180 - BAD - B

        const BD = (AB / angleToSin(ADB)) * angleToSin(BAD)
        const BC = AB + BD
        const AC = (AB / angleToSin(C)) * angleToSin(B)
        if (checkIsRightTriangle(AB, AC, BC)) {
            return C
        }
    }
}

console.log('角 C 的度数是：', computeAngleC())